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authorJack Steiner <steiner@sgi.com>2011-09-21 00:55:04 +0400
committerThomas Gleixner <tglx@linutronix.de>2011-09-21 13:23:15 +0400
commit6a469e4665bc158599de55d64388861d0a9f10f4 (patch)
treeeb33002aa7dfbaae874406220c267284f0353604 /arch/x86/include/asm/page.h
parent9d037a777695993ec7437e5f451647dea7919d4c (diff)
downloadlinux-6a469e4665bc158599de55d64388861d0a9f10f4.tar.xz
x86: uv2: Workaround for UV2 Hub bug (system global address format)
This is a workaround for a UV2 hub bug that affects the format of system global addresses. The GRU API for UV2 was inadvertently broken by a hardware change. The format of the physical address used for TLB dropins and for addresses used with instructions running in unmapped mode has changed. This change was not documented and became apparent only when diags failed running on system simulators. For UV1, TLB and GRU instruction physical addresses are identical to socket physical addresses (although high NASID bits must be OR'ed into the address). For UV2, socket physical addresses need to be converted. The NODE portion of the physical address needs to be shifted so that the low bit is in bit 39 or bit 40, depending on an MMR value. It is not yet clear if this bug will be fixed in a silicon respin. If it is fixed, the hub revision will be incremented & the workaround disabled. Signed-off-by: Jack Steiner <steiner@sgi.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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